Chapter 11 Fossil Fuels - Coal

1. Chapter 11 Fossil Fuels - Coal

2. Fossil Fuels • are • fuels formed from the remains of once living things. • types • coal, oil, natural gas • coal formed from • the remains of swamp vegetation • oil and natural gas formed from • the remains of microscopic marine organisms • All Nonrenewable

3. Nonrenewable Resources • Nonrenewable: • used by humans faster than the earth can create • fossil fuels are still being formed by the same geologic processes but too slowly to replace what we’re using

4. Oil and natural gas Floating oil drilling platform Coal Oil storage Geothermal energy Contour strip mining Oil drilling platform on legs Hot water storage Oil well Gas well Geothermal power plant Pipeline Mined coal Valves Area strip mining Pipeline Pump Drilling tower Underground coal mine Impervious rock Oil Natural gas Water Water is heated and brought up as dry steam or wet steam Water Water penetrates down through the rock Coal seam Hot rock Magma Fig. 16-2, p. 357

5. Coal is a Sedimentary Rock. Coal outcrop in Alaska

6. COAL Countries with largest proven coal reserves • United States (~25%) • Russia (~17%) • China (~13%)

7. COAL Coal reserves in the United States, Russia, and China could last hundreds to over a thousand years. In 2005, China and the U.S. accounted for 53% of the global coal consumption.

9. Known coal deposits could last 200 years at present rate of consumption Notice regions with very little coal – developed or developing countries? Any connection?

10. Coal • solid fossil fuel • occurs in different grades based on variations in heat and pressure during burial • Lignite • Subbitumimous • Bituminous • Anthracite • most, if not all, coal deposits have been identified • primarily in northern hemisphere

11. Increasing heat and carbon content Increasing moisture content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Anthracite (hard coal) Heat Heat Heat Pressure Pressure Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas Fig. 16-12, p. 368

12. Coal Mining Methods Subsurface Mining • Description – excavating a vertical shaft or horizontal tunnel to the resource • Benefits – can get to resources far underground • Costs – more expensive, more time-consuming, more dangerous

13. Surface Mining • Description – if resource is <200 ft. from the surface, the topsoil is removed (and saved), explosives are used to break up the rocks and to remove the resource, reclamation follows • Benefits – cheap, easy, efficient, relatively safe • Costs – tears up the land (temporarily), byproducts produce acid mine drainage that can accumulate in rivers and lakes

14. Surface Mining Strip Mining earth movers strip away overburden, giant shovels remove coal often leaves highly erodible hills of rubble called spoil banks Figure 15-12

15. Surface Mining

16. Surface Mining Strip Mining earth movers strip away overburden, giant shovels remove coal often leaves highly erodible hills of rubble called spoil banks Figure 15-12

17. Surface Mining http://library.ndsu.edu/exhibits/text/greatplains/text.html

18. Surface Mining Contour Strip Mining used on hilly or mountainous terrain if land not restored, a highly erodible bank called a highwall is left Figure 15-13

19. Surface Mining

20. Surface Mining Mountaintop Removal machinery removes the tops of mountains to expose coal waste rock and dirt are dumped into surrounding streams and valleys Figure 15-14

21. Surface Mining

22. Coal-slurry impoundment in the Appalachian Basin. (Photo courtesy of Ben Stout, Wheeling Jesuit University, Wheeling, W. Va.)

23. Acid Mine Drainage http://water.epa.gov/polwaste/nps/acid_mne.cfm#content Environmental Impacts of MiningCoal formation and movement of highly acidic water rich in heavy metals forms through chemical reaction of surface water (rainwater, snowmelt, pond water) and shallow subsurface water with rocks that contain sulfur-bearing minerals, resulting in sulfuric acid Heavy metals can be leached from rocks that come in contact with the acid, a process that may be substantially enhanced by bacterial action.

24. The resulting fluids may be highly toxic and, when mixed with groundwater, surface water and soil, may have harmful effects on humans, animals and plants. Acid mine drainage comes mainly from abandoned coal mines and active mining.

25. Acid Mine Drainage Environmental Impacts of MiningCoal Big problem with abandoned mines Shaft and tunnel systems allow water to come in contact with coal remaining underground

26. Environmental Impacts of MiningCoal • Surface Mining Control and Reclamation Act (1977) • Requires filling (reclaiming) of surface mines after mining • Expensive! • Reduces Acid Mine Drainage • Requires permits and inspections of active coal mining sights • Prohibits coal mining in sensitive areas

27. Environmental Impacts of MiningCoal • Mountaintop Removal • Fills valleys and streams with debris • Strip & Open Pit Spoil Heaps • Debris contains sulfur and mercury

28. Environmental Impacts of BurningCoal • releases large quantities of CO2into atmosphere • Greenhouse gas • releases Mercury into atmosphere • releases Sulfur into atmosphere • Acid Precipitation • Forms Nitrogen oxides also Figure 11.8

29. Environmental Impacts of BurningCoal Source of Pollutants • Coal naturally contains: • Carbon • Mercury • Sulfur • Nitrogen found in atmosphere

30. Environmental Impacts of BurningCoal • Pollutants contained in coal • Carbon • Sulfur • Mercury • Pollutants created by coal • CO2 • sulfur acids and nitrogen acids • mercury – atmospheric, water, land

31. Acid Deposition / Acid Precipitation sulfur released as sulfur oxides when coal is burned sulfur oxides react with water in atmosphere to form sulfuric acid H2SO4 nitrogen in atmosphere = _____% when super heated N2 forms nitrogen oxides nitrogen oxides react with water in atmosphere to form nitric and nitrous acids

32. drawing

33. Environmental Impacts of Burning Coal

34. Environmental Impacts of Burning Coal

35. terms to know • Reclamation • land treatment that minimizes adverse effects from surface mining operations so that mine lands are reclaimed to a usable condition and creates no danger to public health or safety • paid for by mining company, not government • overseen by gov’t agency • Deplete / Depletion • Acid Mine Drainage • Acid Deposition • Overburden

36. How do we make Electricity? • Need fuel source – • to boil water • to make steam • to turn a turbine • to convert mechanical energy into electrical energy • Fuel sources = fossil fuels, nuclear • Exceptions • solar – converts solar energy into electrical energy • wind – turns turbine itself

37. Waste heat Cooling tower transfers waste heat to atmosphere Coal bunker Turbine Generator Cooling loop Stack Pulverizing mill Condenser Filter Boiler Toxic ash disposal Fig. 16-13, p. 369

38. Four widely used devices waste large amounts of energy: Incandescent light bulb: 95% of energy is lost as heat. Internal combustion engine: 94% of the energy in its fuel is wasted. Nuclear power plant: 92% of energy is wasted through nuclear fuel and energy needed for waste management. Coal-burning power plant: 66% of the energy released by burning coal is lost.

39. The major environmental impact common to all fossil fuels is that they: A) are not found everywhere. B) usually have to be processed. C) produce heat when burned. D) produce carbon dioxide. E) have to be transported.

40. The major environmental impact common to all fossil fuels is that they: A) are not found everywhere. B) usually have to be processed. C) produce heat when burned. D) produce carbon dioxide. E) have to be transported.

41. Which type of coal has the highest sulfur content? A. lignite B. subbituminous C. bituminous D. anthracite E. peat

42. Which type of coal has the highest sulfur content? A. lignite B. subbituminous C. bituminous D. anthracite E. peat

43. Which fossil fuel is most abundant in North America? A. oil B. natural gas C. uranium D. coal E. peat

44. Which fossil fuel is most abundant in North America? A. oil B. natural gas C. uranium D. coal E. peat

45. Which fossil fuel reserves will most likely last the longest? A. oil B. natural gas C. coal D. peat E. uranium

46. Which fossil fuel reserves will most likely last the longest? A. oil B. natural gas C. coal D. peat E. uranium

47. Anthracite coal: A. causes the most air pollution B. has the highest sulfur content C. is very hard and is the cleanest burning coal D. is the most abundant grade of coal E. is very soft and burns at high temperatures

48. Anthracite coal: A. causes the most air pollution B. has the highest sulfur content C. is very hard and is the cleanest burning coal D. is the most abundant grade of coal E. is very soft and burns at high temperatures

49. Bituminous coal: A. is the most common grade of coal B. causes the least amount of air pollution of any type of coal C. is very soft and burns at high temperatures D. is very hard and burns cleanly E. has the lowest sulfur content of any type of coal

50. Bituminous coal: A. is the most common grade of coal B. causes the least amount of air pollution of any type of coal C. is very soft and burns at high temperatures D. is very hard and burns cleanly E. has the lowest sulfur content of any type of coal